/* Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.activiti.explorer.ui.reports;

import com.vaadin.data.Item;
import org.activiti.engine.HistoryService;
import org.activiti.engine.ProcessEngines;
import org.activiti.engine.history.HistoricProcessInstance;
import org.activiti.engine.history.HistoricProcessInstanceQuery;
import org.activiti.engine.impl.identity.Authentication;
import org.activiti.explorer.data.AbstractLazyLoadingQuery;

import java.util.ArrayList;
import java.util.List;


/**
 * @author Frederik Heremans
 */
public class SavedReportsListQuery extends AbstractLazyLoadingQuery {

    private static final long serialVersionUID = -7865037930384885968L;

    protected transient HistoryService historyService;

    public SavedReportsListQuery() {
        this.historyService = ProcessEngines.getDefaultProcessEngine().getHistoryService();
    }

    public int size() {
        return (int) createQuery().count();
    }

    public List<Item> loadItems(int start, int count) {
        List<HistoricProcessInstance> processInstances = createQuery().listPage(start, count);

        List<Item> reportItems = new ArrayList<Item>();
        for (HistoricProcessInstance instance : processInstances) {
            reportItems.add(new SavedReportListItem(instance));
        }

        return reportItems;
    }

    protected HistoricProcessInstanceQuery createQuery() {
        // TODO: Add additional "processDefinitionCategory" on HistoricProcessInstanceQuery instead of
        // using variables to find all completed reports. This is more robust and performant
        return historyService.createHistoricProcessInstanceQuery()
                .finished()
                .startedBy(Authentication.getAuthenticatedUserId())
                .variableValueNotEquals("reportData", null);
    }

    public Item loadSingleResult(String id) {
        return new SavedReportListItem(historyService.createHistoricProcessInstanceQuery().processInstanceId(id).singleResult());
    }

    public void setSorting(Object[] propertyIds, boolean[] ascending) {
        throw new UnsupportedOperationException();
    }

}
